Digital audio processing systems can be used for applications such as television, radio, cellular and Internet protocol communications. Audio data can be encoded in a modulated signal using any of a variety of modulation techniques. Some methods of audio data encoding require the use of a phase lock loop to extract the audio data from encoded signals. In addition, audio data can be extracted from some data signals by determining a phase difference between sequential samples of the data signal. However, phase lock loop circuits can be costly or unreliable, and noisy signals can interfere with recovery of phase differences encoded in an audio signal. Therefore, there is a need for an improved digital audio processing system and method.